Long-term skeletal and dental stability after orthognathic surgery of the maxillo-mandibular complex in Class II patients with transverse discrepancies.

INTRODUCTION: Two-jaw surgery has become the standard procedure for correcting skeletal maxillo-mandibular discrepancies in adults. However, only a few studies have reported on the long-term stability of bimaxillary orthognathic surgery in patients with Class II malocclusion and transverse discrepancies. In this study, the long-term outcome of two-piece maxillary treatment during bimaxillary surgery in patients with skeletal Class II malocclusion was examined and the results are discussed. MATERIAL AND METHODS: Dental plaster casts and lateral cephalograms of 47 patients were collected in five phases of treatment: baseline (t1), preoperatively (t2), postoperatively (t3), at the end of orthodontic treatment (t4), and at the time of long-term follow-up (t5), and were retrospectively analyzed. RESULTS: At follow-up all patients showed a Class I occlusion. The maxillary width was, on average, enlarged by 2.7 mm surgically. During the following 8.8 years after treatment, 1.7 mm were lost. The cephalometric analyses showed no severe changes in the sagittal maxillary position for the duration of follow-up. The sagittal mandibular position (SNB) was changed significantly by the mandibular advancement from 75.4° to 77.8° and remained stable for 8.8 years postoperatively. CONCLUSION: Bimaxillary surgery with two-piece maxillary treatment in patients with Class II malocclusion leads to stable long-term occlusal results in the sagittal plane. The transverse enlargement achieved by intraoperative widening does not remain stable over the years. A relapse of about 60% of the surgically expanded transverse width is seen. In Class II deformities without an open bite, where extended transverse enlargement is necessary, a two-step procedure with primary surgically-assisted rapid palatal expansion followed by one-piece surgery should be planned.

A new technique for sandwich osteoplasty with interpositional bone grafts for fixation.

PURPOSE: To present a new technique for sandwich osteoplasty in the posterior mandible and to evaluate its feasibility as part of dental implant treatment. MATERIALS AND METHODS: A retrospective study of sandwich osteoplasty in the posterior mandible was conducted. No osteosynthetic material was used to stabilize the osteotomy. Fixation was achieved with the interposition of two bone blocks harvested from the retromolar region. RESULTS: Eighteen patients with 26 sites of severe atrophy of the posterior mandible were treated. After a healing period of 4 months, 53 dental implants were inserted into the augmented region. The implants were loaded with single crowns or fixed dental prostheses 3 months after placement. The mean vertical bone gain after 4 months of healing was 4.2 mm (standard deviation 1.4 mm). The average bone loss between augmentation and implantation was 2.3 mm (35.4%). All implants osseointegrated and showed no clinical signs of peri-implantitis. In three subjects, the elevated bony segment perforated the lingual mucosa near the adjacent teeth after excessive elevation (> 6 mm) but healed without any sequelae. CONCLUSION: An alternative method for vertical alveolar ridge augmentation of the posterior mandible is presented. No osteosynthetic material is required for fixation, and related complications can be avoided. Further prospective clinical studies are required to demonstrate the feasibility of this technique versus the conventional sandwich osteoplasty.

Altered position of the medial lingual nutritional foramina at different stages of alveolar ridge atrophy.

To determine the altered location of the medial lingual nutritional foramina in different stages of bone resorption, 55 cadaveric mandibles were selected for this study from a total of 1532. Prevalence, location of the foramen (lingual, cranial, labial), application of Atwood classification (grades 1-6), and macroanatomic dissections were tools of this examination. An increasing grade of atrophy leads to a shift in position of the medial lingual nutritional foramen.

Hemorrhage secondary to interforaminal implant surgery: anatomical considerations and report of a case.

Understanding the anatomy of the floor of mouth is very important as severe submandibular hemorrhages are life threatening. This case report illustrates the potential hemorrhage consequences of implant surgery within the interforaminal region. The highly vascularized interforaminal region is susceptible to hemorrhage, which can be induced simply by instruments causing vascular trauma. The risk of intraoperative bleeding can be minimized by painstaking preoperative clinical and radiological examination but cannot be averted as it is inherent in the underlying anatomy of the region.

Simultaneous maxillary sinus lifting and implant placement with autogenous parietal bone graft: outcome of 17 cases.

The aim of this study was to retrospectively evaluate the surgical technique of sinus floor elevation with autogenous parietal bone grafting in conjunction with immediate dental implants for the reconstruction of the maxilla in deficient maxillary alveolar ridges. Seventeen patients who underwent sinus floor elevation with bone graft from the parietal bone between 2005 and 2007 were included in the study. Cases of extremely deficient bone level in the alveolar ridge<4mm were included in the study. Seventy-seven implants (49 Staumann®, 24 Replace® and 4 Ankylos®) with different length and diameter were placed immediately after the graft was placed. Strict oral hygiene was required for the patients. Presurgical and postsurgical panoramic radiographs were taken. A high-quality reconstruction with an increase in lifted sinus bone height was achieved with parietal bone particulates. Seventy-three implants were clinically osseointegrated and four implants were lost giving a success rate 94.8%. No correlation was found between failure and the surgery. The encouraging results of this study suggest that the technique of reconstruction of the sinus floor and the resorbed alveolar ridge using an autogenous parietal bone graft is reliable, giving the surgeon the opportunity to successfully perform immediate implant placement in more difficult and deficient maxillary alveolar bone height.

Le Fort I sliding osteotomy--a procedure for stable inferior repositioning of the maxilla.

INTRODUCTION: Inferior repositioning of the maxilla for correction of vertical maxillary deficiency has been found to be associated with instability and a tendency to relapse. This can not be completely controlled by using bone grafts as relapse commences before complete integration of the graft. METHODS: Improved stability was sought by using rules of geometry when displacing the maxilla down a sloping plane. Anterior and inferior sliding of the maxilla after a double 'M'-shaped Le Fort I osteotomy was performed to preserve bony contact at the medial and lateral maxillary buttresses. The plan of this technique was derived from model surgery when true changes at the Le Fort I level were visualized. PATIENTS: 15 patients with class III-malocclusion and anterior vertical deficiency of the maxilla were surgically treated using this technique. RESULTS: Bony contact at the maxillary buttresses after anterior and inferior displacement was possible in patients with less than 6mm movement in a sagittal direction. Only minor skeletal relapse (mean: 0.4mm) was observed in the follow-up period (mean 14.2 months). CONCLUSION: The procedure should be considered whenever vertical maxilla relapse is of concern after anterocaudal displacement.